The invention relates to a method and a system for manufacturing a catheter and to a catheter manufactured by that method.
Known methods of manufacturing catheter tubing are extrusion and dipping. Advantages of the extrusion process are that it is well-controlled and provides a catheter tubing with a smooth thin wall of a very constant thickness. However, extrusion requires relatively expensive machinery end tools. Therefore, it is mainly suitable for the production of substantial lengths of catheter tubing having a uniform cross-section, To manufacture a catheter, the catheter tubing has to be cut to the required length(s) and fittings have to be connected to the tubing. To avoid blood damage when the catheter is brought in contact with a pationt's blood in-vivo, special adhesives have to be used and smooth transitions at the fittings are required. Furthermore, catheters generally comprise reinforcement material which is uncovered when the catheter is cut to the required length. Special measures are required to cover the reinforcement material to avoid contact between a patient's blood and the reinforcement material.
In UK patent application 2 187 670 it is described to manufacture a catheter having a funnel portion of rubber or other suitable material by placing the funnel over a former and dipping the catheter with the former one or more times in a latex solution.
However, dipping has been found difficult to control and did not provide satisfactory results, as is described in "Transarterial Blood Pumps, Feasibility Phase, Final Report"; Authors: H. Duffor at al.; Ed.: Dr Or G. J. Verkerke and Dr G. Rakhorst--Groningen ISBN 90-74280-02-1.
Furthermore, a particular requirement of catheters to be brought in direct contact with a patient's blood is that the ends and transitions at fittings are as smooth as possible and that all surfaces to be contacted with blood consist exclusively of biocompatible materials which cause as little damage as possible to the blood.